Fastening sheet metal members



Sept. 5, 1939. B, Q PLACE 2,172,258

FASTENING SHEET METAL MEMBERS Filed Sept. 19, 1936 @muy ` novel fastener u the facility of a screw, but which Patented Sept. 5,1939 v UNITED STATES PATENT "OFFICE Devices, Inc., Detroit, Mich Michigan a corporation of Application Seltember 19, 1936, Serial N o. 101,873

l8 Cllims. (Cl. 85-32) '111e present invention is concerned with a. and method for the securing-of sheet metal members having aligned openings. More particularly, the invention is concerned with a fastener that is capable of with the facility of a screw, but sheet metal members together in tion after the manner oi a rivet.

Screws, bolts and rivets are now the fasteners commonly employed to secure two overlapped metallic members together.- Screws and bolts may be readily applied, but they have the disilxedly holds applied posithe parts specially.

The primary purpose of the present invention is to provide a fastener that may be applied with secures members together with the certainty of characterizing a rivet.

Another object of the invention is to provide a novel threaded fastener having a circumferential groove into which the metal of one of the members, secured by the fastener, is forced upon completion of the operation of threading the fastener into holding position.

Still another object of the invention resides in the provision of a novel combination includ` ing specially formed openings in a member to and a fastener Still another object of the invention is to provide an improved fastener having a buttress thread and a circumferential groove into which the spiral groove formed by the buttress thread opens. said buttress thread being an unscrewing action. y

.Another object of the invention resides in the provision of an improved method for, in effect, riveting two superposed members having aligned being appliedv oanings into xedly secured relation to each o er. 1

Still further objects of the invention will apof the present invention.

Figure 2 is a view similar to Figure 1, but showing the metal member after it has been sub- .iected to a die-shaping operation to portion adjacent said opening in-to the desired form for the reception of a threaded fastener.

Figure 3 is a sectional view taken on the plane indicated by the line 3 3 in Figure 2.

Figure 4 is a side view of the preferred form of fastener forming anv important part of the present invention.

Figure 5y is a modified form of fastener.

lng a modified arrangement and modied fastener.

Like reference characters indicate like parts throughout the several iigures.

'I'he present invention requires the formation configuration,A said openingv outline as'illustra'ted in Figure 1. ates fromthe opening IL -In the form A slit I2 radiside of the slit I2 is disposed substantially higher than that of the other side as lllustratedin Figorder to bring the fastener having a is more fully 87,292, filed June 25, 1936.

The preferred form of fastener. illustrated in Figure 4 of the drawing, comprises a head il and a shank l0. The shank il is provided with a screw thread i1 extending from the end of the shank inwardly toward the head. Preferably, the thread I1 is a buttress thread, as illustrated. for a pu later to be described. A circumferential groove il is formed in the shank adiapreferably groove formed by thread i1. The shank of the fastener also, preferably, includes apart il of cylindrical form, and, preferably, of larger diameter than the diameter at the bottom of the il thus provides a shoulder at the end of the threaded portion of the shank. The spiral groove formed by the thread i1 opens into the circumferential groove il, that is, the spiral groove extends into said circumferential groove.

The iastener lust described is used in the msm ner illustrated in Figures 6 and '1, Figure 8 showing the position of the fastener after it has been threaded in the outer member i0 by engagement with the helical wall i4 of the protuberance i2. 2i designates a fragment of the member that is to be secured to the member i0. Member 2| is provided with circular opening 22 having a diameter equal to the diameter of the portion il of the fastener so that when the screw is in holding position the member 2i cannot sluit with respect to the screw. The fastener is brought into the turning the ance until the head i5 of the fastener contacts with the under surface of the member 2i.

Further rotation of the fastener, by means of a screw driver in the slot 23, causes the conical protuberance i3 to be flattened and upon further rotation of the screw the sheet metal is caused to be moved into the circumferential groove it and in back of the shoulder 20. The diameter of the fastener at the bottom of the groove il preferably is slightly greater than the minimum cross dimension of the irregular opening ii so that when the metal of the conical protuberance is forced back into its original plane the shank of the bottom of the circumferential groove IB will be firmly gripped so that the fastener fits snugly in the opening in the member lil. After the fastener has been turned to the position illustrated in Figure '1, it will be understood that the members ill and 2i are secured together after the manner of a rivet. Inasmuch as the conical protuberance i2 has been flattened and the metal is incapable of re-entering the spiral groove formed by the thread i1, the member i0 cannot accordingly be detached from the member 2i without cutting fastener as is necessary in a riveted connection. Inasmuch as the buttress thread i1 presents a surface to the conical protuberance more nearly parallel to the plane of the outer surface of the sheet metal member il such a thread is more effective in attening the conical protuberance than an ordinary tapered thread Howevena thread of any other known form may be used and the present invention contemplates the use of such a fastener.

`In this form of the `meaning and range or breaking the portion Il, that is. it serves to prevent shifting of the metatl member with respect to the screw, the base of the cone being formed to snugly fit in the opening in said member.

In the modincation of the invention illustrated sheet metal member il is providedv with a conical protuberance of the kind illustrated in Figures 2 and 3, and said member is secured to the member 2l by means ofa further modied form of fastener comprising a head 24 and a shank 2l having a buttress thread 2i formed from the end thereof inwardly toward the In this form of the invention no groove is formed in the shank 25 adjacent the head 2l. In securing the Figure 8 the screw is ical protuberance i2 the outside of the member 2i. Upon further rotation of the screw the flat under surface of the buttress thread 26 forces the edge of the conical protuberance toward the outer surface plane of the member il. Said edge accordingly rmly grips the screw until. further rotation thereof is prevented, relian being placed upon the gripping of the edge of the conical protuberance of the screw to prevent reverse rotation thereof. invention the holding action is similar to that of application Serial No. 87,292, already referred to, and reliance is placed on the frictional or biting grip of the edgeof the conical protuberance on the shank of the fastener to prevent reverse rotation of the screw. The buttress threaded through the contive in causing the edge of the protuberance to be forced inwardly toward the shank. A tapered thread has some tendency to enlarge the opening. For this reason the buttress thread constitutes an important part of vthe invention tion illustrated in Figure 8. Of course, a square thread, which is the full equivalent of a buttress thread in the present situation, may also be used. The invention may be embodied in other specific forms without departing from the spirit or essential characteristics thereof. The present embodiment is therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims rather than by the foregoing description, and all changes which come within the of equivalency of the claims are therefore intended in be embraced therein.

What is claimed and desired to be secured by United States, Letters Patent is:

l. A fastener having a head shank having a and a shank, said portion adjacent said head the walls of an opening in one of the members secured by the fastener, a spiral groove formed in said shank from the end thereof remote from said head, and a circumferential groove between said portion and said spiral groove having a width corresponding to the thickness of the member engaged by the fastener, said spiral 70 groove extending into said circumferential groove.

2. A threaded fastener designed for threading into a sheet'metal member having a head and a until the head contacts with` of the modifica- 4 40' thread of this form of the invention is very eifec' shank provided with a circumferential groove rof 16 greater depth than the depth of the groove formed by the thread, said groove being disposed between said head and the thread, and a shank portion between said head and said circumferential groove and spacing said last named groove from said head.

3. In combination, two superposed members having aligned openings, and a fastener having a head bearing against one of said members adjacent the opening therein, and a shank 'passing through and snugly fitting in the openings, said shank having a groove of a width corresponding to the thickness of one of said members providing an annular shoulder lapping said last named member and bearing rmly against said member adjacent said opening and a threaded portion beyond said shoulder and commencing at a point adjacent the outer side of said member.

4. In combination, two superposed members having aligned openings, one of said members having a slit extending radially of its opening, and a fastener having a head bearing against one of said members, and a shank passing through and snugly fitting in the openings, said shank having an annular shoulder parallel to said head and spaced from said head a distance equal to the combined thickness of said members and bearing against said member having a slit and lapping said last named member, and' a threaded portion beyond said shoulder, the pitch of the thread of said last named portion substantially exceeding the thickness of said member. having the slit.

5. In combination, two superposed members having aligned openings, one of said members having a slit extending radially of its opening, and a fastener having a head bearing against one oi' said members, and a shank passing through the openings, said shank having a cylindrical portion fitting snugly in the opening in the other of said members, and a shoulder parallel to said head spaced from said head a distance equal to the sum of the thicknesses of said members and bearing firmly against said member having a slit and lapping said last named member, and a threaded portion beyond said shoulder. I

6. A headed fastener having a shank comprising a cylindrical portion formed to fit Within an opening in a member secured by the fastener, a second cylindrical portion of different diameter from said first portion and formed to t snugly in an opening in a second member through which said fastener is threaded, and a threaded portion beyond said last named portion having a spiral groove of a pitch exceeding thevlength of said second named cylindrical portion.

7. In combination, two superposed sheet metal members having aligned openings of different diameters and cylindrical shape, said members being flat and in contact with each other around said openings, land a threaded fastener having a head bearing against one of said members and cylindrical shank portions of different diameters fitting snugly in the openings in said members, and a threaded shank portion wider than one of said first named cylindrical shank portions extending away from the other member and providing a substantially complete annular shoulder spaced from said head a distance equal to the combined thickness of said members and overlapping said other memberuaround the opening therein.

8. In combination, two superposed members having aligned openings, and a fastener having a head bearing against one of said members adjacent the opening therein, and a shank passing through the openings, said shank having a groove of a width corresponding to the thickness of the other of said members providing a shoulder lapping and bearing firmly against said other member adjacent the respective opening, and a threaded portion beyond said shoulder, the pitch of said threaded portion substantially exceeding the thickness of said other member.

BION C. PLACE. 

